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BACKGROUND AND OBJECTIVE: To determine the amount of interoperator and interinstrument variability introduced into retinal nerve fiber layer (RNFL) thickness measured with Stratus OCT and Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA) in normal and glaucomatous eyes. PATIENTS AND METHODS: Thirty-seven eyes from 37 subjects (20 normal and 17 with glaucoma) were included in the study. Each eye was scanned with one Stratus OCT and one Cirrus OCT by two operators. The eyes were then scanned with a different Stratus OCT and Cirrus OCT by one of the operators. Average, quadrant, and clock-hour RNFL measurements were compared between operators and between instruments after determining the proportion of variance due to subjects, operators, and instruments by means of variance component analysis. RESULTS: Significant differences were observed between Stratus OCT instruments, but not between Cirrus OCT instruments, in average ( P = .01), inferior ( P = .006), and nasal ( P < .001) quadrant RNFL thickness in glaucomatous eyes. Interoperator differences in RNFL thickness measured with both types of instruments were non-significant. The interoperator variability ranged from 0% to 1% on Stratus OCT and was 0% on Cirrus OCT, whereas the interinstrument variability ranged from 0% to 3% for Stratus OCT and from 0% to 1% for Cirrus OCT. CONCLUSION: The interoperator variability of RNFL thickness measured with Stratus OCT and Cirrus OCT, as well as the interinstrument variability of measurements obtained with Cirrus OCT, are non-significant. However, there is significant variability between RNFL measurements performed on two different Stratus OCT instruments.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and safety of implantation of a second glaucoma drainage device for eyes that have failed a primary device. PATIENTS AND METHODS: Medical records of patients receiving a primary glaucoma drainage device at Bascom Palmer Eye Institute from January 1987 to October 1998 were reviewed, of which 18 eyes of 18 patients were studied. Patients failing a primary glaucoma drainage procedure and receiving a second glaucoma drainage device were included in this study. The second eye in the same patient was excluded if a second drainage implant was required. All patients received a second device in a standardized fashion with the drainage tube inserted in the anterior chamber. Main outcome measures included: visual acuity, intraocular pressure (IOP), antiglaucomatous medication, length of follow up, and surface area of glaucoma drainage device. Success was defined as an IOP less than or equal to 2 1 mm Hg with or without medications, and at least a 20% reduction in IOP, without the need for additional glaucoma procedures. RESULTS: The mean postoperative IOP (19.6 ± 9.4 mm Hg; range, 8-50 mm Hg) was significantly (P = 0.006) lower than the mean preoperative IOP (29.5 ± 8. 1 mm Hg; range, 20-52 mm Hg) at last follow up (mean 19.6 ± 13.6 months; range, 6-47 months). The mean number of postoperative antiglaucomatous medications (2.2 ± 1.2; range 0-4) was statistically similar (P = 0.2) to mean preoperative number of antiglaucomatous medications (2.6 ± 1.2, range 1-4). Using Kaplan-Meier estimates, successful IOP reduction was observed in 89%, 83%, 63%, and 37% of eyes at 6 months, 1, 2, and 3 years, respectively. Four patients (21%) had a decline in visual acuity. CONCLUSIONS: Implantation of secondary glaucoma drainage devices may be useful in eyes that have failed primary devices. [Ophthalmic Surg Lasers 2002;33:37-43]

* BACKGROUND AND OBJECTIVE: To evaluate the potential benefits, complications, and prognostic risk factors for failure of phacotrabeculectomy performed with or without 5-fluorouracil (5-FU) and mitomycin-C (MMC). * PATIENTS AND METHODS: Retrospective chart review of 78 patients who underwent phacotrabeculectomy during a 2-year period. Patients were divided into 3 groups, those who received 5-FU (N=28), MMC (N=29), or no antifibrotic agent (N=21). * RESULTS: All 3 groups had statistically significant lower intraocular pressures (IOP) on fewer antiglaucomatous medications at 6-month, 12-month, and last follow-up compared to preoperative levels (P * CONCLUSIONS: Phacotrabeculectomy is effective regardless of antimetabolite use. Race is a strong predictor of failure. [Ophthalmic Surg Lasers 1999;30:367-374.]

BACKGROUND AND OBJECTIVE: To compare rates of abnormal peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer scans acquired with Cirrus HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) and RTVue-100 (Optovue Inc., Fremont, CA) in healthy myopic eyes. PATIENTS AND METHODS: Forty-one non-glaucomatous myopic eyes (41 individuals) were scanned with Cirrus to measure RNFL and ganglion cell-inner plexiform layer (GCIPL) and with RTVue to measure peripapillary RNFL and ganglion cell complex (GCC) thicknesses. Rates of abnormal scans were calculated and compared between devices. Inter-device agreement in falsely classifying scans as abnormal was also assessed. RESULTS: The rate of abnormal average and four-quadrant RNFL was 4.8% to 7.3% on Cirrus and 2.4% to 9.7% on RTVue ( P > .05). The overall rate of abnormal scans was 19.2% on Cirrus and 29.3% on RTVue ( P = .3). Rates of abnormal Cirrus average and segmental GCIPL (12.2% to 17%) were similar to those of RTVue average and segmental GCC (9.7% to 14.6%) ( P > .05). The overall rate of abnormal GCIPL (36.6%) was higher than that of GCC (14.6%) ( P = .023). The inter-device agreement was poor for average RNFL (κ = −0.09), very good for average ganglion cell (κ = 0.81), and fair for overall RNFL (κ = 0.35) and overall ganglion cell (κ = 0.34). CONCLUSION: The high rates of abnormal RNFL and ganglion cell layer scans on both devices call for caution, particularly when attempting to diagnose glaucoma in myopic eyes using these devices. The RNFL and ganglion cell layer analyses may not be interchangeable on either of these devices. These two devices are not interchangeable for classifying healthy myopic eyes based on RNFL or ganglion cell layer analysis.

BACKGROUND AND OBJECTIVE Measurements performed on fundus images using current software are not accurate. Accurate measurements can be obtained only by calibrating a fundus camera using measurements between fixed retinal landmarks, such as the dimensions of the optic nerve, or by relying on a calibrated model eye provided by a reading center. However, calibrated spectral domain OCT (SD-OCT) could offer a convenient alternative method for the calibration of any fundus image. PATIENTS AND METHODS The ability to measure exact distances on SD-OCT fundus images was tested by measuring the distance between the center of the fovea and the optic nerve. Calibrated SD-OCT scans measuring 6 × 6 × 2 mm centered on the fovea and the optic nerve were analyzed in 50 healthy right eyes. The foveal center was identified using cross-sectional SD-OCT images, and the center of the optic nerve was identified manually. The SD-OCT scans were registered to each other, and the distances between the center of the optic nerve and fovea were calculated. The overlay of these SD-OCT fundus images on photographic fundus images was performed. RESULTS Any image of the fundus could be calibrated by overlaying the SD-OCT fundus image, and the measurements were consistent with previously defined calibration methods. The mean distance between the center of the fovea and the center of the optic nerve was 4.32 ± 0.32 mm. The line from the center of the optic nerve to the foveal center had a mean declination of 7.67 ± 3.88°. Mean horizontal displacement and vertical displacement were 4.27 ± 0.29 mm and 0.58 ± 0.29 mm, respectively. CONCLUSIONS The overlay of the SD-OCT fundus image provides a convenient method for calibrating any image of the fundus. This approach should provide a uniform standard when comparing images from different devices and from different reading centers. [Ophthalmic Surg Lasers Imaging 2008;39:S15-S20.]

Double composite grafting is a technique used in the repair of large (>75%) eyelid defects due to tumor resection, trauma, or congenital coloboma. The procedure utilizes two partial thickness composite grafts derived from two unaffected lids. The skin defect is covered by a pedicle skin graft to provide an adequate blood supply. This is thought to be superior to revascularization occurring from the margin of the graft alone. We examined histologically the lid margins of two such grafts 2 and 9 months postoperatively. Each demonstrated scarred tarsus and absent meibomian glands. One of the two grafts had loss of cilia. The architecture of the graft tissue otherwise was preserved.